So I finally took my 10.5" KAK barreled 308 pistol for a test function run. Didn't take long to get the Seekins adj gas block dialed in however I ran into an issue.

Used a little winchester and some 1980's malaysian surplus. Intermittently, I would pull the trigger and *click*. I'd then manually eject the round and there would be a couple light gouges on the bullet. I eventually realized after this happened a few times that the bolt was not fully seating and I could use the forward assist to completely close the bolt and fire the round.

Just throwing this out there to get ideas for my next trip. I have another BCG that's unused I will try next time. I even opened the gas block too much and this would still happen.

Nope. After rifle assembly it was lubed and that's it.

This. ALWAYS clean new parts. With brake cleaner, then oil it again.

Lots of packing and machining oil/grease is not cleaned off before shipping. The packing grease is the worst. You HAVE to clean that shit out. That turns real gummy, really fast when shooting. Almost glue like.

Clean chamber, clean bolt, clean carrier. Get a chamber brush, put it on a drill, and goto town. Not alot of force, but just enough for a little bit. Oil it a few times, then flush it out with oil, and dry it up with a rag.

Try again. Also, make sure you spring and buffer is stiff enough.

As well as cleaning, if you are getting gouges on the bullet, check for burrs on the feed ramps.

And burrs in the leads.

Wonder if its a wee bit tight?

After you get it all cleaned, seperate upper from lower and drop a cartridge in the chamber after marking it w a sharpie so you can inspect for scratches.  If you point the muzzle back up the cartridge should freely fall out.

If that looks good remove the ejector and extractor put the bolt in and twist to lock it in place.  Tou should have no problem locking the bolt in and out this w your fingers w the tectactor and ejecyor removed.  Do this w many instances of different loads.  If you cannot maybe tour chamber is a bit on the tight side.

What brand of mags? I bought a few ASC mags which would drag my bolt (PSA PA-10) causing it to not go fully into battery.
I had to open up the feed lips to cure that problem. No issues with P-Mags.

Thanks for the suggestions everyone I'll follow up with them.

As far as mags I used pmag, Lancers and the 20rd metal ones I got off the brownells with the bright green cartridge shaped follower. Same results so it's gotta be one of the issues posted here. Thanks.

I see you have a KAK shooter. There was a problem with the PA-10 and extractor pressure. The bolt had 2 springs and a rubber O-ring.
The fix there was removing the inner spring and relieving extractor inward pressure which was causing problems similar to yours.
Just another thing to check.

Well I used an brownells nitride bcg and toolcraft nib bcg and same results. Cleaned the chamber yesterday here's how it looked after about 2 magazines. Is there something I'm missing? Attached File

Here is one of the bullets. I will do some testing with my 16" ar10 with the same ammo and if there's no hiccups I'm going to do one last good chamber run with a brush then contact KAK. Attached File


Tried to pull the barrel to examine my chamber real good but my pot metal multi wrench sucks and so I have a Magpul wrench on order.

first of all, you have a 10" barrel 308, what buffer set up AND trying to run ammo that was designed of a real rifle length 308 format.....what's not to love there?

dwell time and pressure curve issue maybe?

Yeah good point. After several problem free ar15 builds I wasn't prepared for the short barrel 308 clusterfuck.

Those scratches are normal. It's not designed to eject unspent rounds. The bullet scrapes on the free ramps. Nothing you can do about that except don't extract live rounds.

You need a heavier buffers and spring, and possibly one of those fat boy tubes from PRI.

Lots of people have built these, but not many can actually run a full mag dump without malfunctions. Single shots work through the bag, but not dumps.

Thanks. I took a chamber brush on a drill and cleaned the shit out of it. I'm bringing 5 different types of 308 as well as my 16" LFA AR10 I've only shot once in the morning. I expect no malfunctions with the 16" however will run the Malaysian 7.62 through it first.

If a couple mags of that run fine in the 16" I'll move to the 10.5 and try US non milsurp ammo. If I still have problems maybe I'll contact SLR Rifleworks and ask HTF they get their short 308's working.

Yeah I have a seekins adj gb. Today I tried Malaysian, federal and Winchester soft points, pmc fmj, perfecta. All had the same results.

I opened the gas a little more than previous attempts and went down to 1-2 FTFire per mag. Very light primer strikes on the FTF's. This trip I ran into a few FTE's resulting in double feeds.

It's getting better though. I brought my 16" 308 and it ran the Malaysian Surplus like a raped ape. Swapped bcgs, and put pistol lower on 16" no issues.

At this point I've ruled out ammo, anything to do with the lower or trigger and bcg. So it's either a really tight chamber or I need to really break this bitch in and also polish the shit out of the chamber.

Attached File

I think my eyes just vomited.

Yeah, try cleaning the chamber. I dont know about the steel wool, I dont like that fiber type shit, I have only used the stainless steel wool, and not in that manner. But it would work like he said, just be anal about cleaning it after to make sure all that stuff is out of there of it will act like shims in the wrong place. Literally locking you up.

You might need more gas as well, Try start full open and work your way to down no hold back, then click back up a few clicks. I know alot say start closed, but your issue may need the opposite. Could just be you need more oomph back and forth.

Double feed is a mag issue, and its when 2 rounds try to go into chamber. Not when you fail to extract and feed a new round into the dead one in the chamber. Thats just a fail to extract, but reliably feeding. Make sense? Not trying to be picky, but there are certain terms for certain failures for certain reasons, if that makes sense. Helps everyone diagnose shit, helps future readers associate the problem properly if they have similar experiences.

Anyways, Ill echo the chamber cleaning again. It never hurts. And try with full gas just to make sure. If you have, and I missed over it while reading, oops.

I've done this before when experiencing those issues.

Also is the gas tube supposed to protrude that far into the upper?

Maybe just the focus, but looks like the gas tube was cut....

It's the focus. Just an nitrided carbine gas tube. I'll try at full open gas to start next range session. I'm glad it's not an ammo issue because 308 ain't cheap and the Malaysian stuff is 39 cents a round.

Yeah my bad. Didn't experience FTE's until today. However with them came less failure to fires. When cleaning the rifle today I really went at it on the chamber with a brush and then mop on a drill. It was definitely better today. I will get this thing to be reliable!

@762AR556

Attached File

Im blind!

The red isnt too bad, but I just dont like bright colors in general. Im a bah humbug kinda guy. Blood red and black would be nice.

But from the pictures, doesnt look like a bad job, just a bad color.

It could still be an ammo problem, its Malaysian stuff. Just because it works in rifle A, doesnt mean it will work in rifle B. Which sucks sometimes, but it really comes down to tweaking the rifle to run with that ammo. Maybe your port could be too small, in anticipation of the major pressure increase with that short of system.

Also, what bcg, what receivers, what buffer and what spring. Parts break down helps alot too.

You could also be having issues with the bcg and the short gas system not having enough venting. Might need a "better" one, depending on what you have.

Well When I ran 5 types of ammo including the Mal stuff they all did the same thing.

I ordered a heavier buffer, If that doesn't help I'll throw it in the 16" since it's kinda over gassed. Spring is just basic DPMS LR308 carbine length.

Receiver is Matrix Arms, bcg is toolcraft. Had same results with Brownells nitride bcg. Was thinking maybe a JP enhanced bolt would help?